PHOTO FILE NO.: STScI-PF95-18 RELEASE DATE: March 31, 1995
HUBBLE TRACKS JUPITER STORMS
NASA's Hubble Space Telescope is following dramatic and rapid changes
in Jupiter's turbulent atmosphere that will be critical for targeting
observations made by the Galileo space probe when it arrives at the
giant planet later this year.
This Hubble image provides a detailed look at a unique cluster of three
white oval-shaped storms that lie southwest (below and to the left) of
Jupiter's Great Red Spot. The appearance of the clouds, as imaged on
February 13, 1995 is considerably different from their appearance only
seven months earlier. Hubble shows these features moving closer
together as the Great Red Spot is carried westward by the prevailing
winds while the white ovals are swept eastward. (This change in
appearance is not an effect of last July's comet Shoemaker- Levy 9
collisions with Jupiter.)
The outer two of the white storms formed in the late 1930s. In the
centers of these cloud systems the air is rising, carrying fresh
ammonia gas upward. New, white ice crystals form when the upwelling
gas freezes as it reaches the chilly cloud top level where temperatures
are -200 degrees Fahrenheit (-130 degrees Centigrade).
The intervening white storm center, the ropy structure to the left of
the ovals, and the small brown spot have formed in low pressure cells.
The white clouds sit above locations where gas is descending to lower,
warmer regions. The extent of melting of the white ice exposes varied
amounts of Jupiter's ubiquitous brown haze. The stronger the down
flow, the less ice, and the browner the region.
A scheduled series of Hubble observations will help target regions of
interest for detailed scrutiny by the Galileo spacecraft, which will
arrive at Jupiter in early December 1995. Hubble will provide a global
view of Jupiter while Galileo will obtain close-up images of structure
of the clouds that make up the large storm systems such as the Great
Red Spot and white ovals that are seen in this picture.
This color picture is assembled from a series of images taken by the
Wide Field Planetary Camera 2, in planetary camera mode, when Jupiter
was at a distance of 519 million miles (961 million kilometers) from
Earth. These images are part of a set of data obtained by a Hubble
Space Telescope (HST) team headed by Reta Beebe of New Mexico State
University.
Credit: Reta Beebe, Amy Simon (New Mexico State Univ.), and NASA
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